Well, first take a look at some great trigger-free options like Drumagog or Toontrack Drumtracker, just record the mics and replace. Although triggers are great, I use triggers much when mixing live gigs and crappy bands bring pieces of shit drum kits. Then i use TDrum triggers either into a DDrum 3 module (oh what a great piece of gear) my friend has, or into Alesis DMPro, connected to Superior Drummer 2.0.
For studio only:
TDrum Triggers (exact replica of the DDrum, same parts, same box, different color and different name), a bit cheaper than DDrum.
Plug them straight into your preamps, then use drumtracker og drumagog to replace the trigger signal with some real sounds.
Could use one overhead, and then "type in" the cymbals afterwards, or use a pair of OH and actually use those.
If you want a module:
Nothing compares to the DDrum modules, but they don't make those anymore. I've heard the Alesis makes a pretty nice and cheap module named "Alesis Trigger I/O" that has no memory, it just turns triggers into MIDI, you're not paying for being able to load samples into it (that you'll never use anyway)